(1) Field of the Invention
This invention relates to a fuse assembly and more specifically, to a fuse assembly, in which a pluraity of members constituting a housing of the fuse assembly can be mounted tightly and whether a fuse element of the fuse assembly has blown out or not can be easily checked.
(2) Description of the Related Art
In a vehicle as a mobile unit, many electric power transfer lines for transferring electric power itself or signals, such as busbars in an electric junction box such as a junction block, relay box and fuse block, and terminals for electric connection, are disposed.
In the electric power transfer lines, a fuse block, in which many fuses that can be inserted or extracted are disposed, is employed to protect electric circuits of various electrical equipments. (The fuse block may be called a relay box, junction block or electric junction box as the general term since the fuse block may have relays or busbars. In this specification, the aforementioned fuse block, relay box and junction block are hereinafter called an electric junction box as the general term.)
For example, a fuse assembly 101 shown in FIG. 7 has been employed as a fuse for use in the electric junction box. The fuse assembly 101 includes a pair of blade-shaped terminals 102, a fuse element (not shown in the figure) for connecting a pair of the terminals 102 with each other, and a housing 104 made of insulating synthetic resin and the like for receiving each one end of a pair of the terminals 102 and the fuse element.
When the fuse assembly 101 is mounted in the electric junction box, a pair of the terminals 102 is connected to respective receiving terminals of the electric junction box. Through the receiving terminal, an electric power is supplied to one terminal 102 from an electric power source or the like, while various load is electrically connected to an opposite terminal 102.
In the fuse assembly 101, when a current value of an electric power supplied to the one terminal 102 through the receiving terminal or the like exceeds a predetermined current value, the fuse element blows out so as to halt the power supply to the load.
The fuse assembly 101 is preferably provided with a partition wall between a pair of the terminals 102 in order to securely prevent the terminals 102 from making a short circuit with each other after the blowing. The partition wall is, for example, integrally produced with the insulating housing 104.
When the partition wall is set between a pair of the terminals 102, in order to receive each one end of a pair of the terminals 102 and the fuse element into the housing 104, the housing 104 needs to be formed being divided into a plurality of members, for example, two members. In this case, the housing 104 is constructed in a manner that the divided members put and receive a pair of the terminals 102 and the fuse element therebetween.
When the housing 104 is formed with dividing into a pluraity of the members, the clearance may take place between or among a pluraity of the members after the assembly of the housing 104. When the clearance takes place, due to vibrations of a vehicle such as a motorcar, into which the electric junction box is mounted, during the traveling, a pluraity of the members hit with each other in the mounted position of the electric junction box to make a noise, or when things come to the worst, a pluraity of the members might come off from the mounted position.
When the clearance takes place between or among a pluraity of the members and a pluraity of the members hit with each other in the mounted position of the electric junction box due to vibrations of the vehicle during the traveling, the fuse element might be deformed undesirably. Moreover, in the conventional fuse assembly 101, since each one end of a pair of the terminals 102 and the fuse element are received in the housing 104, it has been difficult to check whether the fuse element did blow out or not.
It is therefore an objective of the present invention to solve the above problem and to provide a fuse assembly, in which a pluraity of members constituting a housing of the fuse assembly can be mounted tightly and whether the fuse element has blown out or not can be easily checked.
In order to attain the above objective, the present invention is to provide a fuse assembly comprising: a pair of terminals provided in parallel with each other; a fuse element for connecting a pair of the terminals with each other; a plurality of casing members fit with each other for putting and receiving each one end of a pair of the terminals and the fuse element between a plurality of the casing members; and a plurality of electrically conductive locking claws electrically connected to a pair of the terminals, wherein a plurality of the locking claws are provided to a plurality of the casing members, respectively, protrude toward the outside of the casing member from either a pair of the terminals or the fuse element, and locks up an outer surface of said each casing member.
According to the fuse assembly described above, each locking claw, which protrudes toward the outside of the casing member from either a pair of the terminals or the fuse element, locks up an outer surface of the respective casing member. Thereby, either a pair of the terminals or the fuse element is securely fixed to the respective casing member. The locking claw protrudes toward an outer surface of the casing member, that is, the locking claw exposes to an outer surface of the fuse assembly.
Each casing member of a plurality of the casing members is provided with a locking recess for engaging with the locking claw.
According to the fuse assembly described above, the casing member has the locking recess, thereby the locking claw more securely locks up an outer surface of the respective casing member. Therefore, either a pair of the terminals or the fuse element is more securely fixed to the respective casing member.
The locking claw has a wide part and a narrow part that is narrower than the wide part, the wide part and the narrow part lie in a row along a direction, in which a plurality of the casing members put the terminals and the fuse element therebetween when said each locking claw locks up the outer surface of the respective casing member, said each locking recess is formed from the outer surface of the respective casing member and has a second wide part engaging with the wide part of the locking claw and a second narrow part engaging with the narrow part of the locking claw, and the second wide part and the second narrow part lie in a row along a direction, in which a plurality of the casing members put the terminals and the fuse element therebetween.
According to the fuse assembly described above, the locking claw has a wide part and a narrow part, and each locking recess has a second wide part engaging with the wide part of the locking claw and a second narrow part engaging with the narrow part of the locking claw. The wide part and the narrow part lie in a row along a direction, in which a plurality of the casing members put the terminals and the fuse element therebetween. The second wide part and the second narrow part lie in a row along a direction, in which a plurality of the casing members put the terminals and the fuse element therebetween.
Thereby, when the locking claw engages with the locking recess, either a pair of the terminals or the fuse element is fixed to the respective casing member and in addition, a plurality of the casing member are prevented from relatively displacing along a direction, in which a plurality of the casing members put ends of the terminals and the fuse element therebetween.
The narrow part is situated nearer to either a pair of the terminals or the fuse element than the wide part, and the second wide part is situated more outward from the casing member than the second narrow part.
According to the fuse assembly described above, when the locking claw engages with the locking recess, a plurality of the casing member are more securely prevented from relatively displacing along a direction, in which a plurality of the casing members put ends of the terminals and the fuse element therebetween.
Each terminal of a pair of the terminals is formed in a blade-shape, and the locking recesses are disposed symmetrically with respect to an axial line which is situated at the center of a pair of the terminals and extends along the direction of the length of the terminal.
According to the fuse assembly described above, the locking recess is provided at a symmetrical position with respect to the axial line, thereby a plurality of the casing member can be formed in the same shape with each other.
Each teminal of a pair of the terminals has a first through hole, the fuse element has a pair of second through holes, and said each casing member has: a first projection fitting into the first through hole of one terminal out of a pair of the terminals; a second projection fitting into one second through hole out of a pair of the second through holes; a first hole aligning with the first through hole of an opposite terminal out of a pair of the terminals; and a second hole aligning with an opposite second through hole out of a pair of the second through holes.
According to the fuse assembly described above, the first projection fits into the first through hole of one terminal, while the first hole aligns with the first through hole of an opposite terminal. The second projection fits into the second through hole of the one terminal, while the second hole aligns with the second through hole of the opposite terminal.
Thereby, the first projection of one casing member out of-a plurality of the casing members is fit into the first through hole of the one terminal, then is fit into the first hole of an opposite casing member. The second projection of the one casing member is fit into the second through hole of the one terminal, then is fit into the second hole of the opposite casing member, thereby the casing members can be fit with each other in the housing of the fuse assembly. In addition, the terminals and the fuse elements can be mounted to the casing member.
A pair of the first through holes is disposed symmetrically with respect to an axial line which is situated at the center of a pair of the terminals and extends along the direction of the length of the terminal, and a pair of the second through holes is also disposed symmetrically with respect to the axial line.
According to the fuse assembly described above, a plurality of the casing member can be formed in the same shape with each other.